DRM, among other things, affects battery life

A recent series of tests has shown that DRM, along with a host of other …

Recently found online were the results of some tests conducted on the battery life of various digital music players. Specifically, a range of players were used under various conditions—such as varying file formats or using the backlight—with the goal of determining how much the battery life changes under those conditions.

In the real world, there are plenty of factors that will help drain your battery much quicker than you'd like. For example, while the iPod's 14-hour audio-only rating is acceptable (the first iPods had 8 to 9 hours per charge), I never get that many hours, and in fact, I average less than 8 hours. My battery isn't dying prematurely; rather, I like to have my screen on and browse photos, as well as watch an occasional video and crank the volume up.

Although the article discusses a number of factors that can contribute to shorter battery life, the thing that has bloggers talking is the fact that files containing digital rights management (DRM) drain the battery faster than files with no DRM.

DRM's effect on battery life is not something that immediately comes to mind as one of its manynegativeconsequences, but it makes perfect sense, as all processing requires power. Users often tend to think of power drain primarily in terms of the backlight on the display, playback levels, and repeated use of the device's controls. Often forgotten are factors such as equalization, file size, file format, and yes, DRM—all of which can decrease battery life. If a circuit is active, it's using power. If the processing is more complex, as it would be in the case of DRM, the circuit uses more power. So how much power is lost to DRM? As might be expected, it varies depending on the file format and the type of DRM.

The Archos Gmini 402 Camcorder maxed out at 11 hours, but with DRM tracks, it played for less than 9 hours. The iRiver U10, with an astounding life of about 32 hours, came in at about 27 hours playing subscription tracks. Even the iPod, playing back only FairPlay AAC tracks, underperformed MP3s by about 8 percent.

What we're seeing here is very similar to what happens when you buy a car, only to discover that the gas mileage isn't what was advertised. Battery life is estimated under ideal conditions, and as frustrating as that can be given the fact that the world is never ideal, it is the only measurement that makes even a modicum of sense. There are far too many variables among users to provide a real-world battery life estimate that is anything better than a rough guess. Even the somewhat controlled conditions described above fail to completely eliminate the effects of file format on battery life: in the iPod example, AAC with FairPlay DRM was compared to MP3 with no DRM. Using that as your only guide, it is impossible to estimate whether there are any differences in power drain decoding the MP3 format vs. the AAC.

So, we are left with the following inescapable conclusion: if you want your player's battery to last a long time, let it play straight through the playlist, keep the files small and DRM-free, the volume low, and never use the backlight or any of the controls. Better yet, for longest battery life, keep the player turned off and stored on a shelf. If you decide to actually use the thing, well...your mileage may vary.